Dysphagia is a condition in which a person has difficulty swallowing, characterized by impaired transport of saliva, drink, and food from mouth to stomach. Dysphagia results from disease, or damage, to the neural and/or aerodigestive tract structures that produce swallowing (Logemann, 1998). Often, dysphagia presents in stroke patients, patients with other acute neurological conditions, patients having Parkinson's disease or other neurodegenerative diseases, cerebral palsy or chronic obstructive pulmonary disease (COPD) and/or in response to various cancer treatments, wherein the patient has difficulty in, and/or experiences pain with, swallowing. Likewise, other patients may exhibit various swallowing, speech, salivary and/or oral sensory impairments. Dysphagia compounds these health problems via resultant complications, most commonly aspiration pneumonia secondary to entry of saliva or food into the lungs, dehydration and malnutrition (Smithard et al., 1996). As such, some deaths attributed to stroke, may actually be caused by dysphagia and the resulting complication of pneumonia. These complications may also lead to extended hospital stays, emergency room visits, re-admissions, long-term institutional care and need for expensive respiratory and nutritional support. The cost of dysphagia to North American health care systems is estimated to exceed 1 billion USD annually (Agency for Health Care Research and Quality, US Centers for Disease Control and Prevention). Moreover, because dysphagia is most common among the elderly, its prevalence will increase as the population ages over the next 40 years.
In response, various techniques and treatments have been developed to induce or stimulate swallowing, which can provide various therapeutic benefits to the patient or user. For example, as disclosed in US Pub. No. 2006/0282010A1, entitled Oral Device (the entirety of which is hereby incorporated herein by reference), a device and method for inducing swallowing in a patient includes delivering one or more gas pulses to a predetermined area of the mouth and/or throat. The delivery device includes a molded dental splint that is fitted over the patient's lower teeth and is disposed between the teeth of the user.
Another swallowing therapy is VitalStim, which applies electrical stimulation to the neck overlying the laryngeal muscles with the goal of augmenting laryngeal elevation during swallowing (Freed et al. 2001).